Field of the Invention
The present disclosure generally relates to a display device, and more particularly to a display device configured for advanced mutual capacitance touch sensing.
Description of the Related Art
Touch screens have been one of the most popular user input mechanism in a variety of electronic devices because of their ease and versatility of operation. Such a touch screen allows to identify the occurrence and position of a user's touches on the screen, enabling the electronic device to respond appropriately. Conventionally, touch screen display includes a touch panel overlaid on the front of a flat panel displays such as liquid crystal displays (LCDs) or organic light emitting diode (OLED) displays. Such a touch panel is provided with touch driving lines and sensing lines arranged in rows and columns on a substantially transparent substrate. Touch input is recognized by change in capacitance when an object, such as a user's finger, touches the touch panel.
However, overlaying such a separate capacitive touch sensor panel can add thickness and weight to the display device. For this reason, attempts have been made to implement touch sensor within the display panel. As a result, some of the components in the display panel have been configured to implement a touch sensor. However, using components used in displaying images on the display panel to also function as a part of touch sensor has its downsides. For instance, configurations adopted for implementing touch sensor within the display panel can increase undesired parasitic capacitance, which can lead to unsatisfactory display quality. This is especially true for in-plane-switching (IPS) mode and fringe-field-switching (FFS) mode LCD devices, in which the pixel electrode and the common electrode for controlling the orientation of the liquid crystal molecules are provided on the same side of the liquid crystal layer.
Accordingly, there is a need for a display device with improved configuration for sensing touch inputs on display devices.